Precision of find_root

I am wondering about the precision of find_root. Looking into the documentation (I'm using Sage v. 5.0), there is a comment along with one of the examples that the "precision isn't very good on some machines." At the same time, it says that the routine converges unless it throws an error.

A post response from William Stein clarifies that the function is passed to SciPy which has double precision. So I'm assuming that there may be a way for more precision on some machines, but that one can always count on having at least this much.